Mr Cruddas, founder of CMC Markets, is expected to take on the role imminently as the Conservatives look to increase their financial reserves following last year’s general election.

An announcement confirming his appointment could be as made as early as Monday afternoon.

City sources, however, said he had spent Monday morning telling close associates of the news, following earlier speculation in The Telegraph's Dashwood diary column.

Mr Cruddas was a key backer of the recent "No to AV" campaign, and is known to support Conservative values.

A former resident of Monaco, he has since moved back to the UK and has been resident for tax purposes for two years. A committed philanthropist with a charity in his own name, Mr Cruddas is also involved with The Prince's Trust.